18.social phobia: also called social anxiety disorder; excessive fear of social interactions or situations

19.specific phobia: a phobia that is specific to a particular object or situation

20.systematic desensitization: a behavior therapy technique for overcoming phobias by means of exposure to progressively more fearful stimuli (in imagination or by viewing slides) while remaining deeply relaxed

21.two-factor model: a theoretical model that accounts for the development of phobic reactions on the basis of classical and operant conditioning

22.virtual reality therapy: a form of exposure therapy involving the presentation of phobic stimuli in a virtual reality environment